Deflector for railway car cushioning unit

ABSTRACT

A hydraulic cushioning unit for railway cars includes a cylinder with a piston and piston rod assembly reciprocable therein and which during operation provides for the flow of fluid from a high pressure chamber through the piston rod to a low pressure reservoir. The reservoir is of a flexible boot type having one end connected to an intermediate cylinder head and its other end secured to a portion of the piston rod. Fluid from the high pressure chamber flows through the piston rod and outwardly through radial ports to the reservoir. A cylindrical deflector is positioned on the piston rod in the area of the ports and includes a plurality of openings or slots which are arranged to divide and deflect the hydraulic fluid into a plurality of dispersed streams providing a reduced velocity impact against the inner surface of the flexible boot.

United States Patent 1 Spence et al.

11 3,710,952 51 Jan. 16, 1973 [54] DEFL ECTOR FOR RAILWAY CAR CUSHIONINGUNIT [75] Inventors: John H. Spence; Tung Han Yang,

both of Munster, 1nd.; Steven A. Anderson, Elwood, lll.

[7 3] Assignee: Pullman Incorporated, Chicago, Ill.

[22] Filed: 7 Feb. 17, 1971 [21] Appl. No.: 116,047

[52] US. Cl. ..213/43, 213/8, 267/64 B [51] Int. Cl. ..B6lg 9/08, B6lg9/16 [58] Field of Search ..213/8, 43; 267/64 R, 64 A,

[56] References Cited UNITED STATES PATENTS 3,275,164 9/1966 Peterson..213/43 3,334,757 8/1967 Peterson ..213/43 3,307,842 3/1967 Ellis, Jr..267/64 A 2,222,844 11/1940 Johnson ..188/269 3,458,054 7/1969Thompson... ..213/43 3/1971 Knippel ..213/43 Primary Examiner-Drayton E.Hoffman A!t0rneyHilmond O. Vogel and Richard J. Myers [5 7] ABSTRACT Ahydraulic cushioning unit for railway cars includes a cylinder with apiston and piston rod assembly reciprocable therein and which duringoperation provides for the flow of fluid from a high pressure chamberthrough the piston rod to a low pressure reservoir. The reservoir is ofa flexible boot type having one end connected to an intermediatecylinder head and its other end secured to a portion of the piston rod.Fluid from the high pressure chamber flows through the piston rod andoutwardly through radial ports to the reservoir. A cylindrical deflectoris positioned on the piston rod in the area of the ports and includes aplurality of openings or slots which are arranged to divide and deflectthe hydraulic fluid into a plurality of dispersed streams providing areduced velocity impact against the inner surface of the flexible boot.

2 Claims, 5 Drawing Figures PATENTED JAN 16 I975 SHEET 1 [IF 2 INVENTORSJOHN H. SPENCE TUNG HAN YANG STEVEN A. ANDERSON WQW Y PATENTEDJAH 164975 SHEET 2 [IF 2 INVENTORS JOHN H. SPENCE TUNG HAN YANG STEVEN A.ANDERSON A441?! Q ATT'Y.

DEFLECTOR FOR RAILWAY CAR CUSHIONING UNIT CROSS REFERENCE TO RELATEDAPPLICATIONS retained at one end by means of a retainer stop 17 andAnderson et al. Ser. No. 116,186 Filed: 2-17- BACKGROUND OF THEINVENTION 1. Field of the Invention This invention concerns a hydrauliccushion unit of a type utilized in railway car application fordissipating forces occurring as a result of coupler impacts.

2. Description of the Prior Art Cushioning units of the type to whichthe present invention pertains are disclosed in the William H. PetersonU.S. Pats; No. 3,275,164 patented Sept. 27, 1966, and No. 3,334,757patented Aug. 8, 1967.

SUMMARY It is the primary object of the present invention to provide animproved hydraulic cushioning unit which includes an arrangementpermitting the rapid discharge of a large volume of fluid into aflexible reservoir with the volume being dispersed in a multiplicity ofstreams in order to prevent possible damage to the flexible material ofthe reservoir. The primary objective is achieved by the utilization of adeflector which is attached around the outer peripheral surface of apiston rod, the deflector including a plurality of ports or slotsthrough which hydraulic fluid is directed in widely dispersed streams tothe interior of a flexible boot or reservoir. The multiplicity of slotsprovides for reduced velocity impingement on the inner surfaces of thereservoir. Further, the slots are disposed in an oblique fashion topreventexcessive pressure building up in confined areas of the flexiblematerial which might cause possible ballooning or rupturing of theflexible reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional viewthrough an improved hydraulic cushioning unit;

FIG. 2 is an enlarged cross-sectional view of a portion of a piston roddeflector and flexible boot;

FIG. 3 is an enlarged elevational view of a deflector connected to apiston rod;

FIG. 4 is a cross-sectional view taken substantially along the line 44of FIG. 3; and

FIG. 5 is a cross-sectional view taken substantially along the line 5-5of FIG. 4.

DESCRIPTION OF THE PREFERRED EM BODIMENT- FIG. 1 discloses a hydrauliccushioning unit comprising a cylinder 11 having an inner cylindricalwall surface 12 and an outer cylindrical surface 13. One end of thecylinder 1 1 is closed by means of a cylinder head 14 and the other endof the cylinder 11 is open asindicated at 15. A return spring 16 issuitably positioned around the outer cylindrical wall surface 13 and isa slidable ring 18. The other end of the spring 16 is in engagement witha retainer stop 19 on the cylinder 13 A metering pin 21 includingsuitable metering flutes 22 is rigidly connected to the head 14 andprojects longitudinally within the cylinder 13. A piston 23 ispositioned for reciprocation within the cylinder 11. The piston 23 isprovided on one side with a pocket 24 having a metering valve plate 25movably disposed therein.

The valve plate 25 also includes a metering orifice 26 which cooperateswith the metering pin 21 to provide for the flow of fluid from a highpressure chamber A on one side of the piston to a low pressure chamber Bdisposed on the other side of the piston. A threaded end portion 27 of apiston rod 28 is securely connected to the piston 23. The piston rod 28includes a passageway or bore 29 which receives fluid from the highpressure chamber A and discharges the same through a plurality of radialports 30. A plurality of converging bores 31 are also provided in thepiston rod 28 and communicate with the passageway 29. The piston rod 28also is provided at its end with an end plate 32.

An intermediate cylinder head 33 is positioned within the cylinder 11and includes a longitudinal bore 34 communicating with a cavity 35. Anapertured retainer plate 36 is disposed at one end of the cavity 35 bymeans of a snap ring 37. A movable valve element 38 is adapted to bemoved over the bore 34 in one position to close the same.

A cylindrical boot protector 39 is suitably connected within thecylinder 11 to the intermediate cylinder head 33. The protector 39 ismore specifically described in one of the aforementioned related patentapplications. A flexible boot or hydraulic reservoir 40 has one endthereof connected at 41 to the cylinder head 33. The boot 40 is open atthis end to provide for communication through the bore 34, cavity 35,with the low pressure chamberB. The said open end is indicated at 42 inFIG. 1. The other end of the boot is provided with a circumferentialflange portion 43, as best shown in FIG. 2, and which is held on oneside by means of a stop ring 44 and a sleeve 45 suitably connected tothe piston rod 28 to exert a clamping force on the ring 44 which in turnexerts a clamping force on the 1 flange portion 43.

As best shown in FIGS. 3, 4, and 5, a deflector is designated at 46 andincludes an outer cylindrical wall 48 provided at one end with acircumferentially extending shoulder 49. A plurality ofcircumferentially spaced spacer lips 50 are provided at the other end ofthe cylindrical wall 48 to space and support the deflector 46 about thecylindrical piston rod 28 The shoulder 49 is also provided with a innercircumferential surface or opening 47 which fits about the piston rod28. The cylindrical wall 48 also includes a plurality ofcircumferentially and longitudinally spaced ports or slots 51 which mayvary in size as indicated. The ports 51 include sloping wall portions 52which slope in the direction indicated, i.e., obliquely outwardly. Ports53 in the vicinity of the shoulder 49 slope in an opposite direction andinclude wall portions 54. As best shown in FIG. 5, the shoulder 49 alsoincludes an annular undercut or flange 55. As best shown in FIGS. 1 and2, the deflector 46 is positioned immediately in the area of the portsor bores 30 formed in the piston rod 28. The

deflector shoulder 49 is suitably welded to the exterior one side of asecuring connection which receives the flexible flange portion 43 inclamping relation. Thus with the sleeve 45 exerting a continuing thruston the ring 44 the boot end or flange 43 is tightly connected t theshoulder 49. Y

THE OPERATION In the operation the cushion unit is suitably disposed atthe end of a railway car and connected within the center sill so thatupon an impact upon the coupler the cylinder head 14 and cylinder 11 aremoved in the direction toward the end plate 32 which is rigidly securedto the center sill. This buff movement causes fluid to move from thechamber A through the metering orifice 26 into and through thepassageway 29 and outwardly through the ports or openings 30. Duringthis movement the valve plate is in the position indicated in FIG. 1.Fluid now flows through the ports'30 and through the bores 31 outwardlyfrom the passageway 29. The flow of fluid under high pressure throughthe ports is deflected by means of the deflector 46 which divides highvolume flow into a plurality of widely dispersed streams by means of theopenings 51 and 53. Also fluid flows longitudinally outwardly betweenthe spacer lips 50 into the flexible reservoir 40.

By the dispersion of fluid over a larger area of the flexible boot thereis less likelihood of the reservoir ballooning at one end which cancause rupture or possible damage to the flexible material of thereservoir. The widely dispersedstreams dissipate the fluid pressure overa much larger area and thus boot failure problems are greatlydiminished. Further, the multiplicity of slots or-openings reduces theimpingement velocity against the reservoir inner wall. This resultsbecause of the greater area leading out of the annular space between thedeflector and the piston rod. Fluid flows out of the ports 30 at a'highvelocity into this annular space and this velocity is reduced as itemerges from the ports 51. Thus the impact energy is dissipated andcushioning is achieved with full protection afforded by the deflector 46of the flexible boot 40. After the cylinder 11 and piston 23 have closedthe unit is returned to its original position shown in FIG. 1.

Duringthe closing of the cylinder 1], suitable stop on the center sillof the railway car engage and hold the slidable ring 18 stationary sothat the spring 16 is compressed and after the impact ceases the springof course again returns the unit to its'position shown in FIG. 1.

During the return movement the valve plate 25 is displaced from the endof the passageway 29 so that a large quantity of fluid can return fromthe passageway 29 to the high pressure chamber A'. The converging wouldflow between the circumferential surface of the piston 23 and the innersurface 12 of the cylinder 11. The tolerances are such that a limitedclearance is provided between the piston 23, rings and cylinder wall 12to permit such a limited flow. The aforesaid description of theoperation during buff and draft impacts occur when a car or train is notin over-the-road operation, but is being made up. During over-the-roadoperation, the run-in and run-out, which is always present, causecontinued reciprocation of the pistons and piston rods relative to thecylinders of eachcushion unit. Thus these normal forces of operation andimpact and draft control by the cushion unit provides for substantiallyconstant flow of fluid through the deflector ports. Thus the deflectoris effective to reduce the velocity forces assuring continued long lifeoperation of the flexible reservoir.

Thus it is clear that the objective of the invention has been fullyachieved by the provision of the deflector 46 which permits the largevolume fluid to be widely dispersed and in a direction which will notcause damage to the flexible boot, cause ballooning or other undesirableeffects.

What is claimed is:

1. In a hydraulic cushioning device for railway cars including:

a hydraulic cylinder including a first cylinder head adjacentone endthereof,

a second cylinder head disposed within said cylinder between an oppositeopen end of said cylinder and said first cylinder head, said secondcylinder head having a longitudinal opening therethrough,

a piston slidingly positioned between said cylinder heads and providingon one side of said. piston a high pressure chamber,

a piston rod connected to said piston and positioned for slidingmovement through said longitudinal opening,

said rod having a passageway,

metering means between said piston and said high pressurechamberproviding for the metered flow of fluid from said chamber throughsaid passageway during a buff impact,

a flexible tubular reservoir having'an open end,

means sealingly connecting the other end of said tubular reservoir tosaid piston rod, second means connecting the open end of said reser voirto said second cylinder head, to provide for communication between saidreservoir through said longitudinal opening with a low pressure chamberdisposed on an opposite side of said piston,

said piston rod having aperture means extending substantially radiallyto provide for the flow of fluid to said reservoir from said highpressure chamber during an impact, the improvement comprising:

a deflector including a sleeve having a cylindrical wall extendingcircumferentially around said piston rod,

said wall having a plurality of ports extending substantially radiallyfor. directing a plurality of dispersed streams of fluid from saidpassageway into said tubular'reservoir the walls of said ports extendingobliquely with respect to the longitudinal axis of said piston rod. 2.The invention in accordance with claim 1 said ports comprising elongatedslots with certain of said ,walls of said slots extending obliquely in'one direction and certain others extending obliquely in an oppositedirection.

1. In a hydraulic cushioning device for railway cars including: ahydraulic cylinder including a first cylinder head adjacent one endthereof, a second cylinder head disposed within said cylinder between anopposite open end of said cylinder and said first cylinder head, saidsecond cylinder head having a longitudinal opening therethrough, apiston slidingly positioned between said cylinder heads and providing onone side of said piston a high pressure chamber, a piston rod connectedto said piston and positioned for sliding movement through saidlongitudinal opening, said rod having a passageway, metering meansbetween said piston and said high pressure chamber providing for themetered flow of fluid from said chamber through said passageway during abuff impact, a flexible tubular reservoir having an open end, meanssealingly connecting the other end of said tubular reservoir to saidpiston rod, second means connecting the open end of said reservoir tosaid second cylinder head, to provide for communication between saidreservoir through said longitudinal opening with a low pressure chamberdisposed on an opposite side of said piston, said piston rod havingaperture means extending substantially radially to provide for the flowof fluid to said reservoir from said high pressure chamber during animpact, the improvement comprising: a deflector including a sleevehaving a cylindrical wall extending circumferentially around said pistonrod, said wall having a plurality of ports extending substantiallyradially for directing a plurality of dispersed streams of fluid fromsaid passageway into said tubular reservoir the walls of said portsextending obliquely with respect to the longitudinal axis of said pistonrod.
 2. The invention in accordance with claim 1, said ports comprisingelongated slots with certain of said walls of said slots extendingobliquely in one direction and certain others extending obliquely in anopposite direction.